1. Field of the Invention
The present invention relates to a vessel propulsion apparatus.
2. Description of the Related Art
U.S. Pat. No. 7,867,048 B2 discloses an outboard motor with which an oxygen concentration inside an exhaust pipe is detected by an oxygen concentration sensor. U.S. Pat. No. 7,698,889 B2 discloses an exhaust system for a marine engine in which an oxygen concentration inside an exhaust pipe is detected by an oxygen concentration sensor. A catalyst that purifies the exhaust inside the exhaust pipe is disposed at an upstream side relative to the oxygen concentration sensor. A honeycomb member that captures water flowing in reverse inside the exhaust pipe toward a combustion chamber is disposed at a downstream side relative to the oxygen concentration sensor.